I’m with Ramesh and Jonah. I don’t think it worked. But a caveat: It was an unusual convention speech, in that it was very low-key, and it’s always difficult to predict how out-of-the-ordinary speeches play.
I do think it was a mistake, if he was going to run through the story of their lives together, not to make some acknowledgement of how he let her down (to put it mildly). Failing to do this called into question the credibility of the rest of his account. He may not wanted to do it because he has always felt aggrieved and victimized that his affairs were exposed, and also because it might have been a competing headline on the night she formally won the nomination.
Another problem is that he made the case that she has been a “change-maker,” i.e. a progressive Gradgrind, since the 1970s, which underlined how she has been doing this forever and undermined the argument that she’s a threat to the status quo.